Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Tadahiko Yamamoto is active.

Publication


Featured researches published by Tadahiko Yamamoto.


Circulation | 1997

Short-Acting Nifedipine and Diltiazem Do Not Reduce the Incidence of Cardiac Events in Patients With Healed Myocardial Infarction

Kinji Ishikawa; Shoji Nakai; Toshihiko Takenaka; Ken Kanamasa; Junkichi Hama; Iwao Ogawa; Tadahiko Yamamoto; Miki Oyaizu; Akio Kimura; Kentaro Yamamoto; Hiroshi Yabushita; Ryo Katori

BACKGROUND The administration of calcium antagonists to patients with healed myocardial infarction is a controversial treatment. This study was conducted to elucidate the effect of short-acting nifedipine and diltiazem on cardiac events in patients with healed myocardial infarction. METHODS AND RESULTS A controlled clinical open trial of 1115 patients with healed myocardial infarction was carried out between 1986 and 1994. The patients included 595 who received no calcium antagonist, 341 who received short-acting nifedipine 30 mg/d, and 179 who received short-acting diltiazem 90 mg/d. The primary end points were cardiac events, which were defined as fatal or nonfatal recurrent myocardial infarction; death from congestive heart failure; sudden death; and hospitalization because of worsening angina, congestive heart failure, or premature ventricular contractions. Cardiac events occurred in 51 patients (8.6%) in the no-calcium-antagonist group and 54 (10.4%) in the calcium-antagonist group (odds ratio, 1.24; 95% CI, 0.83 to 1.85), demonstrating that the calcium antagonists did not reduce the incidence of cardiac events. Subgroup analysis revealed no beneficial effects of these drugs for reducing cardiac events in patients with such complications as hypertension or angina pectoris. CONCLUSIONS This study showed that use of short-acting nifedipine and diltiazem in this postmyocardial infarction population was associated with a 24% higher cardiac event rate, but this strong adverse trend did not reach statistical significance.


Journal of Medical Ultrasonics | 2003

Diagnosis of ischemic heart disease with exercise echocardiography: Comparison of images obtained at peak- and post-exercise

Yutaka Hirano; Tadahiko Yamamoto; Hisakazu Uehara; Yoshinao Ozasa; Satoru Yamada; Hiroshi Ikawa; Kinji Ishikawa

Peak-and post-exercise stress echocardiography were compared with respect to ability to detect coronary artery disease in 138 consecutive patients undergoing supine bicycle stress echocardiography. Sixty of these patients had single-vessel disease; 37, double-vessel disease; and 19, triple-vessel disease. Exercise was performed in the 20- to 30-degree left decubitus position on an echo-bed with an ergometer. Exercise started at 50 watts and was increased in 25-watt every 3 minutes and to a maximum of 150 watts. Two-dimensional echocardiographic images were digitized and assigned in a quad-screen format for nonbiased interpretation. Total wall motion score (TWMS) was the sum of the wall motion score, from normokinesis (0) to dyskinesis (4), of 16 segments. Image quality score index (IQSI) was the mean of the image quality scores in all views. All of the patients underwent coronary arteriography. Significant coronary stenosis was defined as≧75% stenosis of the large coronary arteries. Two-dimensional echocardiographic studies were adequate for analysis in 133 patients during the peak-exercise stage (peak-exercise) and in 137 patients 30 to 60 seconds after the end of exercise (post-exercise). TWMS at peak-exercise was higher than at post-exercise, while IQSI at peak-exercise was lower than at post-exercise. Sensitivity at peak-exercise versus that at post-exercise was 91% versus 79% (p<0.05); specificity, 76% versus 85%; and diagnostic accuracy, 88% versus 80% (p<0.05), respectively. We conclude that despite poor image quality on exercise echocardiography, better diagnostic accuracy was attained by assessing wall motion changes at peak-exercise than at post-exercise.


Japanese Circulation Journal-english Edition | 1996

Long-Term Nitrate Treatment Increases Cardiac Events in Patients With Healed Myocardial Infarction

Kinji Ishikawa; Ken Kanamasa; Iwao Ogawa; Toshihiko Takenaka; Takeo Naito; Noriaki Kamata; Tadahiko Yamamoto; Shoji Nakai; Junkichi Hama; Miki Oyaizu; Akio Kimura; Kentaro Yamamoto; Naoko Aso; Miyuki Arai; Hiroshi Yabushita; Ryo Katori


Japanese Circulation Journal-english Edition | 1996

Long-term nitrate treatment increases cardiac events in patients with healed myocardial infarction. Secondary Prevention Group.

Kinji Ishikawa; Ken Kanamasa; Iwao Ogawa; Toshihiko Takenaka; Takeo Naito; Noriaki Kamata; Tadahiko Yamamoto; Shoji Nakai; Junkichi Hama; Miki Oyaizu; Akio Kimura; Kentaro Yamamoto; Naoko Aso; Miyuki Arai; Hiroshi Yabushita; Katori Y


Journal of The American Society of Echocardiography | 2001

Hyperventilation and cold-pressor stress echocardiography for noninvasive diagnosis of coronary artery spasm

Yutaka Hirano; Yoshihisa Ozasa; Tadahiko Yamamoto; Hisakazu Uehara; Satoru Yamada; Kizuku Nakagawa; Hiroshi Ikawa; Kinji Ishikawa


Japanese Circulation Journal-english Edition | 1997

Aspirin Plus Either Dipyridamole or Ticlopidine is Effective in Preventing Recurrent Myocardial Infarction

Kinji Ishikawa; Ken Kanamasa; Junkichi Hama; Iwao Ogawa; Toshihiko Takenaka; Takeo Naito; Tadahiko Yamamoto; Shoji Nakai; Miki Oyaizu; Akio Kimura; Kentaro Yamamoto; Ryo Katori


Internal Medicine | 2000

Intermittent Nitrate Therapy for Prior Myocardial Infarction Does Not Induce Rebound Angina nor Reduce Cardiac Events

Kinji Ishikawa; Tadahiko Yamamoto; Ken Kanamasa; Takahiro Hayashi; Toshihiko Takenaka; Akio Kimura; Masaru Miyataka; Hiroshi Yabushita; Koji Kitayama


Journal of Cardiology | 2001

Contrast agent improves diagnostic value of dobutamine stress echocardiography

Hisakazu Uehara; Tadahiko Yamamoto; Yutaka Hirano; Yoshinao Ozasa; Satoru Yamada; Hiroshi Ikawa; Kinji Ishikawa


Journal of The American Society of Echocardiography | 2002

Diagnosis of vasospastic angina by hyperventilation and cold-pressor stress echocardiography: Comparison to 123I-MIBG myocardial scintigraphy

Yutaka Hirano; Yoshihisa Ozasa; Tadahiko Yamamoto; Kizuku Nakagawa; Hisakazu Uehara; Satoru Yamada; Hiroshi Ikawa; Kinji Ishikawa


Japanese Circulation Journal-english Edition | 1997

Aspirin plus either dipyridamole or ticlopidine is effective in preventing recurrent myocardial infarction. Secondary Prevention Group.

Kinji Ishikawa; Ken Kanamasa; Junkichi Hama; Iwao Ogawa; Toshihiko Takenaka; Takeo Naito; Tadahiko Yamamoto; Shoji Nakai; Miki Oyaizu; Akio Kimura; Kentaro Yamamoto; Ryo Katori

Collaboration


Dive into the Tadahiko Yamamoto's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge